1. Field of the Invention
This invention relates to lubricating compositions and more particularly to improved lubricating compositions and most particularly to a lubricating composition having improved anti-wear/extreme pressure and antioxidant properties.
2. Description of the Prior Art
Over the years, the development of satisfactory lubricating oil and grease compositions for use under extreme pressure, high temperature and high speed conditions has received widespread attention. Consequently, numerous additives have been proposed to enhance the physical and chemical properties of these compositions when intended for such service. Such additives are compounds that generally contain lead, sulfur, phosphorus, halogen (principally chlorine), and carboxylate salts, organic phosphates and phosphites. The list also includes chlorinated waxes, sulfurized unsaturated organic compounds, heavy metal sulfides such as lead sulfide and molybdenum disulfide, and antimony thioantimonate.
These additives, although effective under extreme pressure conditions and high temperature conditions, have certain disadvantages. For example, environmental concerns make lead-containing additives undesirable. Antimony thioantimonate, another widely accepted additive for producing extreme pressure lubricants and greases, is expensive, thus significantly increasing the manufacturing costs of said lubricants. Because of its toxicity, disposal is also costly. There is therefore a need for an extreme pressure additive which is environmentally benign and inexpensive to use. The present invention provides such an additive.